The Irish Aviation Authority has started work on a new Air Traffic Control tower at Dublin Airport.
It's needed for when the new runway is ready for take-off in 2021.
The new tower will be Ireland's tallest structure standing at just under 87 metres.
That's the equivalent of 20 Dublin Buses stacked on top of each other.
The IAA says the tower will ensure visibility of the runways, manoeuvring areas and stands. It will feature a Control Cab to facilitate up to 12 positions, and a base building accommodating staff facilities and electronic systems.